Yes, you can transfer previous years’ ISA subscriptions as well as your current year’s ISA.  This can either be money that has been subscribed in the current tax year or the previous tax year, or a mixture of both. If you transfer ISA money that was subscribed during the current tax year then you must transfer all of it. If you transfer money that was subscribed in a previous tax year then you can transfer either all of it or just some of it.